Fixed static destination size

Examples/Echo.py

@@ -120,14 +120,16 @@ def client(destination_hexhash, configpath, timeout=None):
     # We need a binary representation of the destination
     # hash that was entered on the command line
     try:
-        if len(destination_hexhash) != 20:
+        dest_len = (RNS.Reticulum.TRUNCATED_HASHLENGTH//8)*2
+        if len(destination_hexhash) != dest_len:
             raise ValueError(
-                "Destination length is invalid, must be 20 hexadecimal characters (10 bytes)"
+                "Destination length is invalid, must be {hex} hexadecimal characters ({byte} bytes).".format(hex=dest_len, byte=dest_len//2)
             )
 
         destination_hash = bytes.fromhex(destination_hexhash)
-    except:
-        RNS.log("Invalid destination entered. Check your input!\n")
+    except Exception as e:
+        RNS.log("Invalid destination entered. Check your input!")
+        RNS.log(str(e)+"\n")
         exit()
 
     # We must first initialise Reticulum